Hyperfine induced 1s2s 1S0 → 1s2 1S0 M1 transition of He-like ions J. G. Li, P. Jönsson, G. Gaigalas and C. Z. Dong Eur. Phys. J. D, 51 3 (2009) 313-317 Published online: 09 January 2009 DOI: 10.1140/epjd/e2008-00276-x